Close to the end of last month, the CTR of my AdSense dropped from about 1.6 to 0.8 and has not dropped to 0.2. I’ve been hoping it will rise for days now, but it’s not and it’s really affecting my earnings badly. I haven’t made any change on the site recently and I’ve tried experimenting other ads sizes since then. What can I do to take it back to the right rate?